68% achieved an HBV DNA level <200,000 IU/mL (compared with 2% of controls). Above this threshold has been shown to be associated with increased HBV transmission.

5 of 97 (5%) in the treatment group acquired HBV compared to 18 of 100 in the control group. However, in the per-protocol analysis which excluded infants born to women who withdrew consent, were lost to follow-up, or discontinued therapy there were 0 cases of transmission (0 of 88).

There were no specific safety signals identified in this study. In the discussion, the authors note that the Antiretroviral Pregnancy Registry which includes data from 4013 women who received tenofovir, the rate of birth defects with TDF was 2.4% compared to the general population rate of 2.7%.